Cromwell



(NoModel.) l l G. O. CASE. DOOR KNOB.

No'. 421,670., Patented Peb, 18, 1890.

Iml

144701515555. //7 V51/7 mr.

UNITED STATES ATENT CFFICE.

CROMWELL O. CASE, OF NEV BRITAIN, CONNCTICUT, ASSIGNOR TC P. n

F. CORBIN, OF SAME PLACE'.

DooR-KNoB.

SPECIFICATION forming part of Letters Patent No. 421,670, dated February18, 18,90.

Application filed December 6, 1889. Serial No. 332,778. (No model.) l

To all whom t may concern:

Be it known that I, OBOMWELL O. CASE, a

citizen of the United States, residing' at New.

Britain, in the county of Hartford and State of Connecticut, haveinvented certain new and useful Improvements in Door Knobs, of which thefollowing is a specification.

My invention relates to improvements in door-knobs; andthe object of myimprove- 1o ment is economy in construction, and particularly to enablea sheet-metal knob-shell to be fastened to a cast-metal knob-shank.

In the accompanying drawings, Figure 1 is a plan view of one part of aknob-shell with knob-shank attached. Fig. 2 is a sectional Viewl of thesame on line of Fig. 1. Fig. 3 is a reverse plan view of the lower lpartof the knob-shell. Fig. 4 is a side elevation of the knob-shank. Fig. 5is a plan view of the 2O holding-washer, and Fig. 6 is a sectional viewof the same on line y y of Fig. 5.

I have illustrated only that part of the knob-shell that is secured tothe knob-shank. This part is intended to be used with another 2 5sheet-metal knob shell or cap of any ordinary construction, which willbe secured to the shell shown in any desired or ordinary man- 4ner ofsecuring two such parts together.

The knob-shellAis struck up of sheet metal 3o with a solid end, which isperforated, as at 7, Fig. 3, the contour of said perforation beingsubstantially the same as an end View of the boss or tenou 8 on theknob-shank B. This tenon has in end View a contour which is in the formof a truncated circle or cylinderthat is to say, the form of a cylinderthat is cut away upon two sides, as shown in the plan view, Fig. l. Thecylindrical sides of this tenon are made with overhanging projections,4o preferably by being threaded, as shown in Figs. 2 and 4.

The knob-shell A, as beforestated, has a perforation 7, Fig. 3, whosecontour corresponds with that of the tenon 8. Said shell is seated uponsaid tenon, with its end resting upon the flange 9 of the knob-shank B,the form of the tenon and perforation being suchI that the parts cannotrotate one upon the other. The knob-shank may be of cast-iron,

or of any brittle or hard metal not malleable 5o enough to bepractically riveted. Aholdingwasher lO, having a perforation conformingto the contour of the tenon 8 on the knobshank, is then placed thereon,and the whole secured together by swaging or riveting the washer untilit snuglyrfills the space within the shell surrounding the tenon 8,including the threaded portion of the tenon. The washer of course willbe of malleable metal suitable .for thus riveting-as, for instance,wrought- 6o iron or homogeneous steel. It may be riveted by ahand-setting punch and-hammer; but I prefer that it shall be riveted ina rivetingmachine or power-press.

By this construction I am enabled to readily and firmly secure asheet-metal knob-shell to a knob-shank that is composed of cast-iron orother metal unsuitable for riveting, and thereby produce a knob at asmall cost.

I claim as my invention- 7o The principal part of a knob hereindescribed, the same consisting of the sheet-metal shell A, theknob-shank B, having tenon 8, and the holding-washer 10, the parts beingsecured in place by swaging or riveting said holding-washer,substantially as described, and -for the purpose specified.

ALBERT N. ABBE, C. A. BLAIR.

